ABSTRACT Blackleg disease caused by Leptosphaeria maculans is one of the most devastating diseases of Brassica crops. It causes significant yield loss in canola (oilseed rape) where it is grown in countries/regions like Canada, Australia, and Europe. Genetic resistance is one of the most effective disease management strategies. Blackleg resistance against L . maculans isolate PG4‐1‐M ( AvrLm2 , AvrLm5‐9 , AvrLm6 , AvrLm10 and AvrLm11 ) was introgressed by interspecific hybridisation between the susceptible Brassica napus ‘Westar’ and a resistant hexaploid Brassica hybrid. Resistant backcross progeny (BC 5 F 2 ) (BNHB16) exhibited a hypersensitive response against L . maculans . Resistant backcross progeny did not follow a 3:1 segregation ratio after selfing, or a 1:1 ratio following backcrossing. Different phenotyping and genotyping platforms were explored to determine the presence of novel resistance gene(s) at the BC 5 F 2 and BC 5 F 3 generations. Backcross progeny were screened for Rlm3 , Rlm5 and Rlm6 genes for blackleg resistance with different sets of L . maculans isolates. For genotyping, microsatellite (SSR) markers linked to Rlm6 and rjlm2 were used. In addition, Kompetitive Allele‐Specific PCR (KASP) markers were used to screen for the presence of Rlm2 , Rlm3 , Rlm4 , Rlm7 , Rlm9 and LepR3 . The absence of all these genes following phenotyping and genotyping suggests that this material is likely to contain novel resistance against L . maculans among the backcross progeny. This newly developed germplasm may help to develop blackleg‐resistant canola and rapeseed breeding programmes.

ABSTRACT Agriculture is essential for sustaining life, providing nutrition and contributing trillions of dollars to the global economy. However, increasing global populations and limited natural resources are placing unprecedented pressure on food production systems. These challenges are further exacerbated by plant diseases, environmental pollution and extreme weather events, all of which can significantly reduce crop yields and undermine socioeconomic stability. To ensure food security, there is an urgent need to develop early‐stage plant disease detection systems, optimise resource efficiency and minimise dependence on chemical inputs. Traditional crop inspection methods, which rely heavily on visual assessment and farmer expertise, face significant limitations in accuracy and scalability. In contrast, advanced optical‐based techniques—such as Raman spectroscopy and nanopore sequencing—offer promising alternatives by enabling non‐invasive, highly sensitive and real‐time disease detection. This review explores diagnostic approaches leveraging nanotechnology, as well as emerging advancements in information and communication technology for agriculture. By integrating these cutting‐edge solutions we can revolutionise the global fight against plant pathogens and secure sustainable food production for the future.

ABSTRACT Natural regeneration of Picea jezoensis , one of the dominant conifer species in northern Japan, is severely inhibited by soil‐borne pathogens. Although the snow mould Herpotrichia juniperi is known to inhibit seed germination, several studies have suggested the involvement of other pathogens. To clarify the fungal community infecting P. jezoensis seeds under snow, we performed a seed bag experiment and isolated putative pathogens, combined with DNA‐based species identification and inoculation tests. Moreover, metabarcoding analysis was performed to examine the distribution of the isolated species in foliar litter. The experiment was conducted at 12 sites divided between two different altitudes (500 and 700 m) in a natural forest in Hokkaido, Japan. Various species were isolated from ungerminated P. jezoensis seeds; two species, H. juniperi and Neonectria candida , were the most frequently isolated. The isolation rates of these two species differed between altitudes; H. juniperi dominated at higher altitude sites, whereas N. candida dominated at lower altitude sites, with similar or even higher frequencies than H. juniperi . Metabarcoding analysis revealed a high abundance of isolated species, especially H. juniperi , suggesting that fresh litter serves as a reservoir for opportunistic pathogens and negatively affects the natural regeneration of P. jezoensis .

ABSTRACT Aspergillus flavus infection of corn ( Zea mays ) is a major agronomic concern due to contamination with acutely toxic and carcinogenic aflatoxins. A. flavus populations are very diverse; however, more than 70% of corn isolates produce large sclerotia. There is limited research investigating corn infection by different A. flavus strains. This study tracked corn kernel infection by a small sclerotial strain, Af70‐GFP (S), and a large sclerotial strain, Tox4‐RFP (L), that were engineered to express green and mCherry red fluorescent proteins, respectively. Fluorescence, aflatoxin and A. flavus DNA were assessed to track fungal infection. Near‐infrared light spectroscopy was used to measure kernel nutrient composition. Af70‐GFP (S) was able to establish kernel infection earlier than Tox4‐RFP (L) as measured by fluorescence and droplet digital PCR (ddPCR); Af70‐GFP (S) also produced aflatoxin earlier in infection and in greater quantities. Protein, fat and starch content decreased in corn kernels with longer infection. Af70‐GFP (S) infection resulted in a reduction in kernel starch content, and Tox4‐RFP (L) reduced protein and fat content more than Af70‐GFP (S). Increased starch metabolism probably resulted in greater aflatoxin production by Af70‐GFP (S). This research suggests that A. flavus strains may differ in their abilities to infect corn. Hence, a greater diversity of A. flavus should be assessed in future studies for their virulence to assist in improving biocontrol and resistance technologies.

ABSTRACT Colletotrichum truncatum is one of the causal pathogens responsible for pepper anthracnose disease. Florylpicoxamid is a new quinone inside inhibitor (QiI) fungicide that can strongly inhibit C. truncatum . The current work investigated the resistance risk of C. truncatum to florylpicoxamid and the potential underlying mechanism. The baseline sensitivity of C. truncatum isolates ( n = 111) to florylpicoxamid was established, yielding an average 50% mycelial growth inhibition concentration (EC 50 ) of 0.1362 ± 0.1144 μg/mL. Four stable florylpicoxamid‐resistant C. truncatum mutants were obtained by fungicide adaptation, each exhibiting resistance factors > 600. Notably, each mutant displayed significantly lower fitness compared with that of the parental isolate. Moreover, it was found that florylpicoxamid does not exhibit cross‐resistance with five fungicides (pyraclostrobin, mefentrifluconazole, prochloraz, carbendazim and fluazinam) that are currently used for the field control of pepper anthracnose. All four highly resistant mutants displayed mutations in the cytochrome b (Cytb) protein, S207L. The amino acid substitution S207L in CtCytb, resulted in decreased binding affinity, as determined by molecular docking, of florylpicoxamid to CtCytb. Overall, there seems to be a moderate risk that C. truncatum develops resistance to florylpicoxamid. The mutation, S207L in CtCytb, indeed confers resistance to C. truncatum against florylpicoxamid.

ABSTRACT Bacterial panicle blight (BPB), caused by Burkholderia glumae , is an emerging disease in rice that threatens global food security in the absence of effective strategies to control it. The environmental bacterium Pseudomonas protegens PBL3 produces and secretes a collection of molecules (secretome) with demonstrated antimicrobial activity in vitro against B. glumae , suggesting that this P. protegens PBL3 secretome can be exploited as a source of an environmentally friendly management strategy against BPB. However, the effectiveness of the P. protegens PBL3 secretome under greenhouse and field conditions has not been investigated, as they require large volumes of the active product. In this work, we optimised fermentation conditions to successfully scale up the production of P. protegens PBL3 secretome from 20 mL to 6 L while retaining its antimicrobial activity. Lyophilisation of the P. protegens PBL3 secretome obtained at large scale facilitated testing of several concentrations to identify the minimal inhibitory concentration in vitro and in planta. We further demonstrated that spraying the P. protegens PBL3 secretome at 0.1 g/mL in rice panicles prior to B. glumae inoculation significantly reduced B. glumae populations and BPB symptoms. These results will pave the way towards advancing the use of the P. protegens PBL3 secretome to alleviate the impact of BPB.

ABSTRACT Monilinia fructicola is a major causal agent of brown rot in stone fruit and is recognised as the most aggressive species within the genus Monilinia . Despite its economic impact, the molecular basis of its pathogenicity remains poorly understood, due to the lack of efficient genetic transformation tools. This study aimed to develop and optimise a robust protoplast‐mediated transformation protocol for M. fructicola , providing a foundational platform for functional genomics in this pathogen. To achieve this, different culture media and enzymatic combinations were tested to maximise protoplast yield and viability. Best results were obtained using hyphae grown in Murashige and Skoog (MS) medium supplemented with 0.1 M fructose, and enzymatic digestion with a combination of VinoTaste Pro and Yatalase, yielding up to 3 × 10 7 protoplasts g −1 of fresh mycelium. Regeneration rates reached up to 60% under optimal conditions. Competent protoplasts were transformed with a self‐propagating, unstable telomeric plasmid conferring fenhexamid resistance, achieving a transformation efficiency of 38.8%, within or above the range reported for other filamentous fungi. Upon subculturing transformants under nonselective conditions, the resistance marker was lost in fewer than 50% of cases, suggesting that plasmid persistence in M. fructicola is higher than expected. Although M. fructicola can be transformed efficiently using circular DNA, the limited rate of plasmid loss may require further optimisation to enable full utility in marker‐free genome editing strategies. This work provides an essential step forward in enabling genetic manipulation in M. fructicola , opening the door to advanced tools such as CRISPR/Cas9‐mediated genome editing.